JP2002232422A - System and method for interfacing a network station subsystem - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a technology which enables a client to quickly and efficiently access functions provided in a server interface. According to the present invention, there is provided a method for managing client-server communication, the method comprising:
Serving the client's request by providing the server with functions and interface methods, providing the client with a reference to the interface method, and invoking the interface method on the server via the reference. Ideally, the interface method is
Implemented by providing the server with a table of pointers to the function and providing the client with a reference to the table of pointers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and apparatus for operating a network station subsystem, and more particularly, in one embodiment, to an operational support system for interacting with a cable modem (CM) application. Interface (O
The present invention relates to an interface reference method and system implemented in a client manager (SSI).

[0002]

2. Description of the Related Art The transfer of high-speed data over cable television systems is based on Internet Protocol (I) over cable systems, which are typically all-coaxial or hybrid fiber coaxial (HFC) cable networks.
P) Two-way forwarding of traffic is involved. Referring to FIG. 1 in more detail, the transmission path through such a cable system is implemented at the head end by a cable modem termination system (CMTS) and at each customer location by a cable modem (CM). Is done. At the head end (i.e., hub), the interface to the data-over-cable, or system that sends data over the cable, is known as the Cable Modem Termination System Network Side Interface (CMTS-NSI). At the customer location, the interface is the cable modem to customer premises equipment interface (CM
CI). The system includes, but is not limited to, data, Dynamic Host Configuration Protocol (DHCP), Internet Control Message Protocol (ICM).
P), which functions to forward IP traffic such as IP group addressing (broadcast and multicast) transparently between these interfaces.

[0003] "Network Station Management System and Method (Network Station Mana)
Gement System and Metho
d) co-pending U.S. patent application Ser.
As described more fully in US Patent No. 464,637, a networking manager is a cable modem management task that interacts with application layer Internet Protocol (IP) components to establish and manage Internet connectivity. The contents of the above patent application are incorporated herein by reference. These IP components can include:

[0004] 1. 1. Dynamic Host Configuration Protocol (DHCP) client 2. Configuration Download Trivial File Transfer Protocol (TFTP) Time of day (TOD) client 4. TFTP for downloading new software Simple Network Management Protocol (SNMP) Agent Each application layer component is designed to perform as a separate task. Each of these tasks uses a messaging system (in this particular case, an operating system (OS) -supplied messaging system) and sends data to the networking manager in the body of the message. This task design also enables the networking manager to perform other cable modem management functions by checking application layer task messages only when needed (improving CPU bandwidth utilization).

[0005] The Operations Support System Interface (OSSI) management component is designed based on an object-oriented design concept. The reason for this is to allow enough flexibility to handle the ever-changing OSSI conditions that rely primarily on control mechanisms via Management Information Base (MIB) objects. The Cable Modem OSSI Client Manager is a task created at boot time. It has its own message queue to receive work from the application layer task or from the networking manager task, and it sends messages to the networking manager task.

[0006] Accordingly, the OSSI subsystem architecture is based on a simplified component object model. Each component in this architecture can operate as a server or a client. The server component performs a set of functionality. It exposes its functionality set via an interface. An interface is an immutable convention that defines the interaction between a server component and a client component. Interfaces are represented by a set of methods whose signatures (functional prototypes) never change, but whose implementation may change.

If the client uses the method at the server interface, the client must be able to access the functions via the interface. Accordingly, a need exists for a method and architecture that allows for quick and efficient client access to functions embodied in a server interface.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and solves the above-mentioned drawbacks of the prior art, so that a client can quickly switch to a function embodied in a server interface. It is another object of the present invention to provide a method and an apparatus that enable efficient access.

[0009]

SUMMARY OF THE INVENTION The present invention provides a network station subsystem architecture that uses a simplified interface reference discovery method. More specifically, in one embodiment, a method for managing client-server communication is provided, which provides a server with functionality and an interface method, and provides a client with a reference to the interface method. Serve client requests by serving and invoking interface methods on the server via reference. 1 of this embodiment
According to one aspect, the interface method provides the server with a table of pointers to functions,
And ideally, at design time, a reference to the table of pointers is provided to the client.

According to another embodiment, a method of operating a network device subsystem is provided. The method embodies a first component in a network device, the first component comprising a function and a function pointer corresponding to the function, wherein the second component in the network device includes a function in the first component. Instantiate a second component comprising a reference to a pointer, generate a request from a first component for a function in the second component via a corresponding reference to a function pointer, and transfer the requested function to the second component. Generating a response from the second component to supply to one component.

According to another embodiment of the present invention, there is provided a network device, comprising a server component comprising a plurality of functions and function pointers to the plurality of functions, comprising a reference to the function pointer. A client component, and an interface manager configured to receive requests for functions from the client component and to invoke functions requested by the server component via function pointers.

In accordance with yet another embodiment of the present invention, there is provided a system for managing communications in a network station for a data-over-cable network comprising a plurality of network stations. The system comprises a plurality of components in a network station, each component comprising a set of functionality and a table of pointers to the set of functionality, a station comprising a reference to the table of pointers in the plurality of components. A manager, the plurality of components, and an interface manager in communication with the station manager, wherein the interface manager issues a station manager request for functionality from the component via the interface manager via a reference to a table of pointers. It is configured to process.

[0013]

DETAILED DESCRIPTION OF THE INVENTION Architectural Concepts The OSSI subsystem interacts with the Cable Modem Manager on a request / response basis. An overview of the interaction between the cable modem manager and the OSSI subsystem, in this case, the OSSI client manager, is illustrated in FIG. Typically, a cable modem (CM) manager is configured to generate a request for an OSSI client manager in the OSSI subsystem. The OSSI client manager is configured to process the request and generate a response to the CM manager.

[0014] Based on the content of the request, the OSSI client manager determines which components need to be used to fulfill the request. The OSSI client manager then invokes the method in the appropriate component interface. In one embodiment, the CM manager and OSS
The I client manager ideally references component functions by pointers stored in a table of pointers at each component interface. All data stores referenced by the pointer in the request message can be in the shared system memory area.

B. Design 1. OSSI Client Manager Task The OSSI Client Manager is designed to run as a single-threaded out-of-process application task. Cable Modem Manager (CMM) uses the API ossi
task Create an OSSI client manager task during the cable modem initialization phase by calling create.

The task priority of an OSSI client manager task depends on the hardware and the RTOS platform. Table 1 below shows an example of task priority assignment on two platforms.

[0017]

[Table 1]

2. Interface with OSSI Client Manager The external interface between the cable modem application and the OSSI system is based on a message system. Two message queues are used (a request message queue and a response message queue). Request and response message queues are created and initialized by the OSSI client manager.

A. Request Message Queue The cable manager provides an O by queuing request messages into a request message queue.
Request a specific function to be performed by the SSI Client Manager. The cable modem manager can queue a plurality of request messages in a request message queue. However, OSSI client managers can only service one request message at a time (based on a first come, first served basis). The general format of the request message is shown in Table 2.

[0020]

[Table 2]

I. Requested function code (word 0, bit 3
1-16) The request message code is composed of two ID fields (component and interface).
These two ID fields are primarily for internal use by the OSSI client manager. OSSI
When the client manager receives the request message,
The OSSI client manager picks up the component ID from the requested function code and determines which management component responds to this request from the OSSI management component table. An OSSI management component is identified. The OSSI client manager picks up the interface ID from the requested function code. The OSSI client manager uses this interface ID as a reference pointer in the identified component interface table to fetch the function pointer of the interface method to be invoked. Each required function code is temporarily defined in Table 3 below.

[0022]

[Table 3]

Ii. Function specification parameter 0 (word 0,
Bit 15-0) Function specifying parameter 1 (word 1, bit 31-0) Function specifying parameter 2 (word 2, bit 31-0) Function specifying parameter 3 (word 2, bit 31-0) Execution of requested function All four function-specific parameter fields are used to pass any input parameters needed for this. For those that are not used, the parameter field should be set with a value of 0. OSSI components are in-process (in
-Marshalling and unmarshalling of the parameters is not required since the process is performed.

B. Response message queue The OSSI client manager returns the completion status and response information of the requested function (other than the event notification request) in the response message. All unused fields should be set with a value of 0. The general format of the response message is defined in Table 4 below.

[0025]

[Table 4]

3. Supported Request Features a. Software Upgrade (0x0100) When the Cable Modem Manager recognizes that a need exists for a software upgrade,
The cable modem manager sends this software upgrade request message to the OSSI from either the configuration file or the SNMP manager.
Send to client manager. It is also possible that in the request message, the TFT in function specific parameter 1
The pointer to the P server IP address and the pointer to the name of the software upgrade image in the function specifying parameter 2 are specified. The format of the software download from the configuration file request message is defined in Table 5 below.

[0027]

[Table 5]

Under normal operation, no software upgrade response message is returned to the cable modem manager. The cable modem reboots itself from its new software upgrade image. OSSI Client Manager
If an error is detected during the software upgrade process, it simply returns a response message to the cable modem manager. The format of the software upgrade response message is defined in Table 6 below.

[0029]

[Table 6]

B. Enable CPE / CMIP Host Communication (0x0200) When the cable modem manager decides to enable communication between the CPE and the CMIP host, the cable modem manager sends an enable CPE / CMIP host communication request message to the OSSI client manager. OSSI Client Manager is OSS
OSSICpeIpHos in the I status word
Set the tComm bit. Enable CPE / C
The format of the MIP host communication request message is defined in Table 7 below.

[0031]

[Table 7]

Upon completion of the enable CPE / CMIP host communication request, the OSSI client manager returns a response message to the cable modem manager. The format of the Enable CPE / CMIP Host Communication Request message is defined in Table 8 below.

[0033]

[Table 8]

C. Start CPE / CMIP Host Communication (0x0201) When the Cable Modem Manager decides to activate CPE / CMIP Host Communication, the Cable Modem Manager sends a Start CPE / CMIP Host Communication Request message to the OSSI Client Manager. Start CPE / CMIP host communication interface, API function br bridge CPE and cable modem IP by calling the Bridge component provided by set ()
Enable communication with the host. After setting up communication between the CPE and the cable modem IP host, the OSSICpeIPHostComm bit is set to O
Reset on SSI status word. The format of the Start CPE / CMIP Host Communication Request message is defined in Table 9 below.

[0035]

[Table 9]

Upon completion of the start CPE / CMIP host communication request, the OSSI client manager returns to the one that requested the response message. Start CP
The format of the E / CMIP host communication request message is defined in Table 10 below.

[0037]

[Table 10]

D. Event Notification (0x0202) Any cable modem component can send trap, syslog, enterprise trap, and event log information to a remote network host by sending an event notification request message to the OSSI client manager. is there. A predetermined event code is specified in the function specifying parameter 1 field. If the event code in parameter 1 specifies that this event is for sending an enterprise trap, the request needs to specify a predetermined enterprise number in the parameter 2 field. If sending enterprise traps and reported MIB objects is one element of the MIB object table, the function-specific parameters so that the OSSI can reference that particular MIB object in the MIB object table. An interface index is required in three fields. O
The SSI Client Manager will take the appropriate action (trap, trap,
System log or event log). Any traps or syslogs that are then unable to report are recorded in the event log. The format of the event notification request message is defined in Table 11 below.

[0039]

[Table 11]

Upon completion of the event notification request, no response message is returned to the requestor, ie, the one who made the request.

E. Cleanup event log (0x0
203) Unexpected power loss can blur log entries in the event log. The cable model manager uses the OSSINvsL set in the OSSI status word during a later system boot time.
It is possible to recognize a blurred event log entry by checking the ogWritePending bit, and it must remove incomplete log entries. Cable Modem Manager sends this cleanup event log request message to OSS
Send to I Client Manager. The OSSI client manager removes the blurred log entries from the event log and returns the OSI in the OSSI status word.
Reset the SSINvsLogWritePending bit. The format of the cleanup event log request message is defined in Table 12 below.

[0042]

[Table 12]

Upon completion of the cleanup event log request, the OSSI client manager returns a response message to the cable modem manager. The format of this cleanup event log request message is defined in Table 13 below.

[0044]

[Table 13]

F. Copy event log from NVS to DRAM System memory (DRA) during cable modem initialization
M) in the nonvolatile storage memory (NV).
To synchronize with S), the Cable Modem Manager transfers the system memory (DVS) from the non-volatile storage (NVS).
(RAM) Send this copy event log to the request message. The format of the copy event log from NVS to DRAM is defined in Table 14 below.

[0046]

[Table 14]

Upon completion of the copy event log from NVS to DRAM request, the OSSI client manager returns a response message to the cable modem manager. The format of the copy event log from NVS to DRAM response message is defined in Table 15 below.

[0048]

[Table 15]

G. Copy event log from DRAM to NVS In order to extend the life of the nonvolatile storage memory, it is necessary to reduce the frequency of writing data to the nonvolatile storage memory (NVS). When logging occurs, all event logs are stored in non-volatile storage memory (NV
It is stored in the system memory (DRAM) instead of S). If there is any change in the event log, the cable modem will periodically write back to the NVS to update the system memory (DRA) every 30 seconds.
M) and synchronize the event logs in the non-volatile storage memory (NVS). The format of the event log copy request message from DRAM to NVS is defined in Table 16 below.

[0050]

[Table 16]

Upon completion of the copy event log request from DRAM to NVS, the OSSI client manager returns a response message to the cable modem manager. The format of the copy event log response message from DRAM to NVS is defined in Table 17 below.

[0052]

[Table 17]

H. Reset Event Log When the cable manager receives an SNMP set request for a docsDevEvControl mib object with a value of resetlog (1), the cable manager sends this reset event log request message to the OSSI client manager. The format of the reset event log request message is defined in Table 18 below.

[0054]

[Table 18]

Upon completion of the reset event log request, O
The SSI client manager returns a response message to the cable modem manager. The format of the reset event log response message is defined in Table 19 below.

[0056]

[Table 19]

Although the specific embodiments of the present invention have been described in detail above, the present invention should not be limited to these specific examples, but may be variously modified without departing from the technical scope of the present invention. Of course is possible.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating transparent IP traffic over a data over cable system.

FIG. 2 is a schematic diagram illustrating a general interface with an OSSI client manager according to one embodiment of the present invention.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Harry Hostoff United States of America, California 95130, San Jose, Kingston Way 5012 (72) Inventor Anthony Hun United States of America, California 94566, Pleasanton, Paseo Granada 3077 F-term (reference) 5K030 HD06 JA09 JA10

Claims (24)

[Claims] 1. A method for managing client-server communication, comprising: providing a function and an interface method to a server; providing a reference to an interface method to a client; and an interface on the server through a reference to the interface method. Processing the client's request by invoking the method. 2. The method according to claim 1, further comprising providing a table of pointers to the functions when providing the functions and the interface method to the server. 3. The method of claim 2, wherein providing a reference to the interface method to the client comprises providing a reference to the table of pointers. 4. The method according to claim 3, wherein in processing the client's request, a request from the server for a function from the server is generated by referring to the pointer table for the requested function. And generating a response from the server to provide the requested function via the table of pointers. 5. A method for operating a network device subsystem, the method comprising: executing a first component in a network device, the first component comprising a function and a function pointer corresponding to the function; and a second component in the network device. Executing a second component comprising a reference to a function pointer in the first component, and requesting a request from the first component for one of the functions in the second component via a corresponding reference to the function pointer. Generating a response from the second component to provide the requested functionality to the first component. 6. The method of claim 5, wherein when executing the first component, providing a table of function pointers. 7. The method of claim 6, wherein when executing the second component, providing a reference to a table of the function pointers. 8. The method of claim 7, wherein when generating a request from the first component, referencing a table of pointers to the requested function. 9. The method according to claim 8, wherein when a response is generated from the second component, a request from the first component is received and a requested function is invoked via a table of the pointer. how to. 10. A method of interfacing communication in a network station for a data over cable network having a plurality of network stations, wherein each component in the network station is a table of a functional set and a pointer to the functional set. Providing a plurality of components comprising: a station manager comprising a reference to a table of pointers in the plurality of components; and communicating with the plurality of components and the station manager. Providing an interface manager to address functionality from the component via the interface manager via a reference to the pointer table; That processes the station manager request, wherein the. 11. The method of claim 10, further comprising: when processing a station manager request, generating a request at the station manager for functionality via a reference to the table of pointers and at the interface manager. Receiving a request and invoking functionality from the requested functionality set via the table of pointers. 12. The method of claim 11, wherein the requests for the functionality are processed serially by the interface manager. 13. The method of claim 11, wherein the requests for functionality are processed by the interface manager on a first come, first served basis. 14. The method according to claim 11, wherein, when preparing the plurality of components, storing data referred to by the pointer in a shared memory area. 15. A network device, comprising: a server component including a plurality of functions and function pointers to the plurality of functions; a client component including a reference to the function pointer; and a function from the client component. A network device comprising: an interface manager configured to receive a request to the server component and invoke a function requested by the server component via the function pointer. 16. The network device according to claim 15, wherein the client component requests a function via a reference to a function pointer. 17. The apparatus of claim 16, wherein the interface manager is configured to receive a reference to a function pointer and determine a function requested to invoke via the reference to the function pointer. Network device. 18. The network device according to claim 15, wherein the server component includes a table of pointers to the functions. 19. The network device according to claim 18, wherein said client component is configured to refer to said function via said pointer table. 20. A system for managing communication in a network station for a data over cable network comprising a plurality of network stations, the system comprising a plurality of components in the network station, each component comprising a functional set and the functional set. A plurality of components comprising a table of pointers to functionality sets; a station manager comprising a reference to a table of pointers in the plurality of components; and communicating with the plurality of components and the station manager. An interface manager for accessing functionality from the component via the interface manager via a reference to the table of pointers; A system comprising: an interface manager configured to process a station manager request. 21. The station manager of claim 20, wherein the station manager generates a request for functionality via a reference to the table of pointers and sends the request for functionality to the interface manager. A system wherein the interface manager is configured to receive a request for the functionality and to invoke functionality from the requested functionality set via the pointer table. 22. The system of claim 20, wherein the interface manager is configured to process requests for functionality serially. 23. The system of claim 20, wherein the interface manager is configured to process requests for functionality on a first-come, first-served basis. 24. The system according to claim 20, further comprising a shared memory area for storing all data referred to by said pointer.